mm: count writeback pages per BDI
Count per BDI writeback pages.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/backing-dev.h b/include/linux/backing-dev.h
index bfae09d..4d9222c 100644
--- a/include/linux/backing-dev.h
+++ b/include/linux/backing-dev.h
@@ -28,6 +28,7 @@
enum bdi_stat_item {
BDI_RECLAIMABLE,
+ BDI_WRITEBACK,
NR_BDI_STAT_ITEMS
};
diff --git a/mm/page-writeback.c b/mm/page-writeback.c
index 9b3c4ee..f1d201f 100644
--- a/mm/page-writeback.c
+++ b/mm/page-writeback.c
@@ -979,14 +979,18 @@
int ret;
if (mapping) {
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
unsigned long flags;
write_lock_irqsave(&mapping->tree_lock, flags);
ret = TestClearPageWriteback(page);
- if (ret)
+ if (ret) {
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
+ if (bdi_cap_writeback_dirty(bdi))
+ __dec_bdi_stat(bdi, BDI_WRITEBACK);
+ }
write_unlock_irqrestore(&mapping->tree_lock, flags);
} else {
ret = TestClearPageWriteback(page);
@@ -1002,14 +1006,18 @@
int ret;
if (mapping) {
+ struct backing_dev_info *bdi = mapping->backing_dev_info;
unsigned long flags;
write_lock_irqsave(&mapping->tree_lock, flags);
ret = TestSetPageWriteback(page);
- if (!ret)
+ if (!ret) {
radix_tree_tag_set(&mapping->page_tree,
page_index(page),
PAGECACHE_TAG_WRITEBACK);
+ if (bdi_cap_writeback_dirty(bdi))
+ __inc_bdi_stat(bdi, BDI_WRITEBACK);
+ }
if (!PageDirty(page))
radix_tree_tag_clear(&mapping->page_tree,
page_index(page),